Shape memory alloys may be used to form an actuator that has unique thermal and mechanical properties. These types of actuators may be referred to as shape memory alloy (SMA) actuators. For example, if a shape memory alloy is plastically deformed while in a martensitic state and then heated to a phase transition temperature to reach an austenitic state, the shape memory alloy morphs back to its original, non-deformed shape. The rate of return to the original, non-deformed shape depends upon the amount and rate of thermal energy applied to the shape memory alloy.
SMA actuators may be activated by heating the shape memory alloy to its phase transition temperature, which causes the shape memory alloy to undergo a phase transformation from the martensitic to the austenitic state and morph back to its original, non-deformed shape. SMA actuators may be used in variety of applications such as, for example, an airfoil system for an aircraft. However, SMA actuators have, in at least some instances, proved challenging to control. For example, an SMA actuator may be activated by a resistance heating element. One drawback to this approach is that the resistance heating element may not heat the shape memory alloy of the SMA actuator quickly enough to its phase transition temperature. Accordingly, there exists a need in the art for improved techniques for controlling SMA actuators.